1. Field of the Invention
The invention is a flow restriction detector for a nozzle assembly of a liquid dispensing machine, particularly for an edible liquid packaging machine used in the food industry.
2. Description of the Prior Art
The invention was developed for use in a machine for packaging milk or cream in small cups for use with coffee or tea. Large quantities of these milk or cream cups are used by the food service industry, which in turn require dairies to have packaging machines capable of meeting the huge demand. High speed liquid packaging machines have been developed to provide the necessary production capability for these packaged milk or cream cups under aseptic conditions. Such machines can produce 1600-2100 filled and sealed cups per minute. Obviously, it is important that a blockage or partial blockage of the flow of liquid from a nozzle of such a packaging machine be detected at an early stage. Nozzle blockages are detectable during production through the mismatched filling of cups, and a blockage during production usually requires a shut down of the run to locate and clear the obstruction. Accordingly, it would be preferable to have a means for detecting a nozzle blockage prior to a production run, and the invention addresses this need.
The cup filling station of a high speed liquid packaging machine has a nozzle assembly capable of filling a plurality of cups simultaneously as they pass rapidly beneath the nozzles. For example, a nozzle assembly may comprise an array of four rows of six nozzles, with each row being fed by a liquid distributing body in fluid communication with a central reservoir. A nozzle assembly of this design is capable of filling 24 cups simultaneously. Blockage or partial blockage of any one of the 24 nozzles in an assembly can be caused by such things as fragments from gaskets or seals entering the fill system, or simply from the buildup of butter fat or other milk solids.